allow group shares, even if not all public keys are available

apps/encryption/lib/crypto/encryption.php

@@ -390,7 +390,11 @@ class Encryption implements IEncryptionModule {
 				$publicKeys[$this->keyManager->getMasterKeyId()] = $this->keyManager->getPublicMasterKey();
 			} else {
 				foreach ($accessList['users'] as $user) {
+					try {
 						$publicKeys[$user] = $this->keyManager->getPublicKey($user);
+					} catch (PublicKeyMissingException $e) {
+						$this->logger->warning('Could not encrypt file for ' . $user . ': ' . $e->getMessage());
+					}
 				}
 			}
 

apps/encryption/tests/lib/crypto/encryptionTest.php

@@ -304,7 +304,6 @@ class EncryptionTest extends TestCase {
 		$this->assertSame($expected,
 			$this->instance->update('path', 'user1', ['users' => ['user1']])
 		);
-
 	}
 
 	public function dataTestUpdate() {
@@ -330,6 +329,43 @@ class EncryptionTest extends TestCase {
 		$this->instance->update('path', 'user1', []);
 	}
 
+	/**
+	 * Test case if the public key is missing. ownCloud should still encrypt
+	 * the file for the remaining users
+	 */
+	public function testUpdateMissingPublicKey() {
+		$this->keyManagerMock->expects($this->once())
+			->method('getFileKey')->willReturn('fileKey');
+
+		$this->keyManagerMock->expects($this->any())
+			->method('getPublicKey')->willReturnCallback(
+				function($user) {
+					throw new PublicKeyMissingException($user);
+				}
+			);
+
+		$this->keyManagerMock->expects($this->any())
+			->method('addSystemKeys')
+			->willReturnCallback(function($accessList, $publicKeys) {
+				return $publicKeys;
+			});
+
+		$this->cryptMock->expects($this->once())->method('multiKeyEncrypt')
+			->willReturnCallback(
+				function($fileKey, $publicKeys) {
+					$this->assertEmpty($publicKeys);
+					$this->assertSame('fileKey', $fileKey);
+				}
+			);
+
+		$this->keyManagerMock->expects($this->never())->method('getVersion');
+		$this->keyManagerMock->expects($this->never())->method('setVersion');
+
+		$this->assertTrue(
+			$this->instance->update('path', 'user1', ['users' => ['user1']])
+		);
+	}
+
 	/**
 	 * by default the encryption module should encrypt regular files, files in
 	 * files_versions and files in files_trashbin